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Notes in italics from Hertfordshire by Nikolaus Pevsner and Bridget Cherry (2002)
Yale University Press, New Haven and London.

One of Lutyens's most remarkable churches. Red brick with stone dressings. No tower, but excessively far-projecting roof eaves. Of the three bays of the nave only one was built by Lutyens, 1914-15, the rest completed by Sir Albert Richardson in 1963-4 with a cupola at the W end.

The aisle is separated from the nave by little arches on Tuscan columns, three arches per bay. Big and high transepts two bays deep. Between the two, separating the transepts from the crossing, one colossal Tuscan column on each side, deliberately dwarfing those of the arcades of the the aisles. ... The interior is all white with a timber ceiling supported by the walls and the two giant transept columns.

Similar small arcades on the outer sides of the transepts.